Separation system

ABSTRACT

A mechanical separation system is disclosed which includes a stud member and a stud housing maintained in mating engagement by a piston. The stud member has a plurality of externally-threaded segments fingers which can be formed in an overall conical shape so that the major diameter of the threaded portion of the conically-shaped fingers is less than the minor diameter of the corresponding internal threads in the stud housing. The piston is positioned within the segmented fingers of the stud member to force the fingers radially outwardly so that the threaded portions mate with the corresponding threads in the stud housing. Separation of the stud member from the stud housing is accomplished by displacing the piston to allow the stud fingers to move inwardly to assume a conical shape. The externally threaded portion of the stud member is thus disengaged from the internal threads of the stud housing to permit separation of the stud member from the stud housing. In an alternative embodiment, the fingers of the stud member are not formed into a conical shape prior to use, but the energy imparted to the fingers as they are threaded into the stud housing is sufficient to cause the fingers to be deflected inwardly and to disengage from the housing when the piston member is forced out of contact with the end portions of the fingers.

United States Patent Steele et al.

[4 1 Oct. 10, 1972 [54] SEPARATION SYSTEM [72] Inventors: Michael F.Steele, Costa Mesca; John S. Yates, Placentia, both of Calif.

{73] Assignee: The Susquehanna Corporation, Fairfax County, Va.

[22] Filed: Dec. 21, 1970 [21] Appl. No.: 99,917

3,114,962 12/1963 Brown ..29/200D Primary Examiner-Thomas l-l. EagerAttorney-Tipton D. Jennings 5 7] ABSTRACT A mechanical separation systemis disclosed which includes a stud member and a stud housing maintainedin mating engagement by a piston. The stud member has a plurality ofexternally-threaded segments fingers which can be formed in an overallconical shape so that the major diameter of the threaded portion of theconically-shaped fingers is less than the minor diameter of thecorresponding internal threads in the stud housing. The piston ispositioned within the segmented fingers of the stud member to force thefingers radially outwardly so that the threaded portions mate with thecorresponding threads in the stud housing. Separation of the stud memberfrom the stud housing is accomplished by displacing the piston to allowthe stud fingers to move inwardly to assume a conical shape. Theexternally threaded portion of the stud member is thus disengaged fromthe internal threads of the stud housing to permit separation of thestud member from the stud housing. In an alternative embodiment, thefingers of the stud member are not formed into a conical shape prior touse, but the energy imparted to the fingers as they are threaded intothe stud housing is sufficient to cause the fingers to be deflectedinwardly and to disengage from the housing when the piston member isforced out of contact with the end portions of the fingers.

13 Claims, 4 Drawing Figures PATENTFID 10 3,696,488

sum 1 of 2 I ze 24 2a 22 INVENTORS MICHAEL F STEELE JOHN S. X4TE$ AGENTSEPARATION SYSTEM BACKGROUND AND SUMMARY OF THE INVENTION The presentinvention relates to a mechanical separation system. More particularly,the present invention relates to a mechanical separation system which iscapable of withstanding high tensile and compression loads while capableof being actuated to effect separation by a relatively small force.

Many separation mechanisms in use today, including pyrotechnic actuatedthrustors, employ the brute force method of accomplishing separation.This method of separation consists of fracturing or rupturing the mainload carrying components of the mechanism to effect mechanical releaseand structural separation. Such prior art mechanisms require that thedevices with which such separation mechanisms are employed be capable ofwithstanding extreme forces during the separation process. In addition,many of these devices must employ special shrouds to contain fragmentsand to provide safety for personnel handling such devices.

By the present invention there is provided a separation mechanism whichdoes not require the fracturing of any load-carrying components. Theforce necessary for actuation and subsequent separation of the mechanismof the present invention is a function of the torque applied to themechanism during assembly; hence selection of the energy-producingactuator is simple and straight forward. The axial tensile orcompression load-carrying capability of the separation mechanism can bemany times greater than the actuation force. In addition, all componentsof the mechanism can be completely captive after separation within theassemblies which are being separated and may be reused withoutdegradation to performance. Special shrouds for containing fragmentsobtained in the separation process as in prior art devices are thereforeunnecessary. Also, simplicity of design enables the mechanism to beproduced economically with a high degree of performance reliability.

The separation system of the present invention includes an internallythreaded stud housing, and a stud member having a plurality ofextemally-threaded segmented projections or fingers which can be formedin an overall conical shape. The major diameter of the threaded portionof the conically-shaped fingers is less than the minor diameter of thecorresponding internal threads in the housing for the stud member. Apiston member is adapted to be positioned within the segmented fingersof the stud member to expand or flex the fingers radially outwardly sothat the threaded portions of the stud member can engage thecorresponding threads in the stud housing. Separation of the stud memberfrom the stud housing is accomplished by displacement of the pistonwithin the stud member to allow the fingers of the stud member to moveinwardly sufficiently to disengage the threaded portions of the fingersfrom the internal threads of the stud housing. Separation may also beeffected by displacing the piston outwardly from the stud member. In .analtemative embodiment, the projections or fingers are not formed into aconical shape prior to use but extend parallel to the longitudinal axisof the stud member. In this latter embodiment, energy developed when thefingers are threaded into the stud housing causes the fingers to moveinwardly sufficiently to disengage the threaded portions of the fingersfrom the internal threads of the stud housing when the piston member hasbeen displaced from engagement with the extremities of the fingers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view incross-section showing the separation mechanism constructed in accordancewith the principles of the present invention with the fingers of thestud member flexed outwardly by the piston member so as to engage thestud housing;

FIG. 2 is a side elevational view similar to FIG. 1 showing the pistondisplaced inwardly and the fingers of the stud member in an unflexedconical position;

FIG. 3 is an end view in cross-section of the segmented fingers orprojections of the stud member taken along line ll in FIG. 1;

FIG. 4 is a side elevational view partly in cross-section of a thrustormechanism which employs the separation system of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of thepresent invention as shown in FIG. 1, 2 and 3 there is provided aseparation system 10 which includes a stud housing 12, a stud member 14,a piston 16 and a shaft 18.

The stud member 14 includes a threaded shaft 20 or other suitable meansfor attachment of the structure or component that is to be separated.The separation end 22 of the stud member 14 is formed in a tubular shapeand provided with external threads 24. Slots are formed longitudinallyin the separation end 22 to provide a plurality of threaded segmentedfingers or projections 26. The stud housing 12 is formed with an innerrecess 25 within which the stud member 14 is receivable. There is alsoprovided in the stud housing 12 an opening 19, preferably cylindrical inshape, through which a shaft 18 can extend. The threaded fingers 26 ofthe stud member 14 can be formed in a conical shape as shown in FIG. 2,by swaging or other conventional means, with the major diameter of thethreads 24 on the conically-shaped stud member being less than the minordiameter of the internal threads 28 formed in the stud housing 12. Thepiston 16 is of cylindrical construction, preferably in the shape of acylindrical disk, and adapted to be slidably movable within the innercircumference of the fingers 26 in the separation end 22 of the studmember 14. When installed in the stud member at the extremity of thefingers 26, the major diameter of the piston 16 is of a size sufficientto force the swaged fingers 26 of the stud member 14 to flex outwardlyto their unswaged diameter as shown in FIG. 1, thus engaging theexternal threads 24 of the stud fingers 26 with the internal threads 28of the stud housing 12. As previously mentioned, the stud member 14 mayalso be formed with the threaded fingers 26 parallel to the longitudinalaxis of the stud member 14. In this configuration, the energy developedwhen the fingers 26 are threaded into the stud housing 12 causes theends of the fingers to be deflected inwardly when the piston member 16is forced out of contact with the end portions of the fingers 26, thusdisengaging the external threads 24 of the fingers 26 from the internalthreads 28 of the stud housing 12 and allowing the stud member to beseparated from the housing.

During operation, the piston 16 can be displaced by means of alongitudinally-extending shaft 18 so that the piston 16 moves to aposition within the tubular portion of the stud member 14 forward of thesegmented fingers 26, thus allowing the fingers 26 to assume a conicalshape in disengaged relation with the stud housing 12. The housing 12member 14 can then be separated. In an alternative (not shown), theshaft 18 can be secured to the piston 16 so that as the shaft 18 ismoved outwardly from the stud member 14, the piston 16 is forcedoutwardly into an opening (not shown) in the stud housing 12, thusdisengaging the piston 16 from the segmented fingers 26 of the studmember 14 and allowing the segmented fingers to assume a conical shapein disengaged relation with the stud housing 12.

In FIG. 4 there is shown a thrustor 30 in which the separation system ofthe present invention can be employed. .Such apparatus can include, inaddition to the separation mechanism 10, a shear pin 32 for locking theshaft 18 to the housing 12 and a series of 0- rings 35 and retainerrings 36. A pressure source 34 or other means may be provided forimparting an axial force to the shaft 18 in order to displace the piston16 located within the stud member 14 and thus to effect separation.

Assembly of the separation mechanism of FIGS. 1, 2 and 3 is accomplishedby inserting the piston 16 in the tubular end of the stud member 14 andpositioning the piston 16 at the outer end of the fingers 26 of the studmember 14 in order to force the fingers outwardly so that they can bejoined in mating engagement with the threaded inner portion 28 of thestud housing 12. The stud member 14 is then threaded into the studhousing 12. Preferably, sufficient torque is applied to the stud memberthat the forces tending to maintain the union between stud member 14 andstud housing 12 exceed the maximum operating load to which theseparation system may be subjected. Such a preload torquing force alsoproduces normal forces upon the segmented fingers 26 in contact with thepiston 16, efiecting positive piston retention and displacing thefingers 26 inwardly when the piston 16 is forced away from theextremities of the fingers 26.

Actuation and separation of the stud member from the stud housing isaccomplished by applying an axial force to the shaft greater than thefrictional force developed between the segmented fingers and the pistonduring installation. This applied force drives the piston 16 forwarduntil it abuts the inner face of the tubular section of the stud member14. This movement of the piston 16 permits the segmented fingers 26 ofthe stud member 14 to deflect inwardly to assume a conical shape andthus to disengage from the mating threads of i forces involved, oneembodiment of a separation system constructed in accordance with thepresent invention was subjected to a tensile force of about 10,000

pounds. While subjected to such a tensile force, the

axial force required for separation was about 260 pounds.

The separation system of the present invention can be used to separate avariety of mechanically-joined components. Specific applications includeutilization of the present separation system in the jettisoning ofrocket motors, the separating of rocket payloads and as a replacementfor explosive bolts. Since separation of the mechanism is not dependentupon a large shock force, any type of suitable force-producing mediumcan be used as pressure source 34, including hydraulic, pneumatic,electromechanical or other equivalent means. Actuation can beaccomplished by either pushing or pulling the piston. When the piston ispulled out of the tubular portion of the stud member in order to effectseparation, the fingers of the stud member will assume a conicalconfiguration and any tensile forces acting between the stud member andstud housing will cause the stud member 14 and stud housing 12 toseparate.

The stud housing vl2 and the piston 16 can be fabricated from aluminumor other similar lightweight material having high structural strength.The stud member 14 canbe made from stainless steel or other similarmaterial. Preferably, the piston 16 es of a material which is dissimilarto that of the stud member 14 in order to reduce friction between theperiphery of the piston 16 and the internal surfaces of the segmentedfingers 26 of the stud member 14.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent that various changes may be made in the instant constructionwithout departing from the spirit and scope of the invention orsacrificing its material advantages, the fonn hereinbefore describedbeing merely a preferred embodiment thereof.

It is claimed:

1. A separation system comprising:

a. a stud member having a plurality of externally threaded projectionsdisposed about the longitudinal axis of the stud member, saidprojections having end portions which are displaceable inwardly relativeto said longitudinal axis,

. a piston member movably mounted within the stud member and retained bysaid projections at their end portions, said piston member being of suchsize as to maintain said projections in a position parallel to saidlongitudinal axis,

c. threaded means for engaging said extemallythreaded projections, and

. said piston being movable in a direction along the longitudinal axisof the stud member relative to said projections to permit saidprojections to become disengaged from said threaded means, thereby toseparate said stud member from said threaded means. I

2. The system of claim 1 wherein the projections normally have anoverall conical shape.

3. The system of claim 3 wherein said threaded means includes a studhousing having an intemallythreaded portion which is engageable with thethreaded projections of said stud member when the projections are in aposition parallel to said longitudinal axis.

4. The system of claim 3 wherein the major diameter of the threadedprojections of the stud member is normally less than the minor diameterof the intemallythreaded portion of the stud housing.

5. The system of claim 4 further including means associated with saidstud housing for displacing the piston member within the stud member.

6. The system of claim 4 further including means associated with saidstud housing for displacing the piston member outwardly from'the studmember.

7. The system of claim 1 wherein said threaded means includes a studhousing having an intemallythreaded portion which is engageable with thethreaded projections of said stud member.

8. The system of claim 7 further including means associated with saidstud housing for displacing the piston member within the stud member.

9. The system of claim 7 further including means associated with saidstud housing for displacing the piston member outwardly from the studmember.

10. A separation system comprising:

a. a stud member having a plurality of externallythreaded projectionsdisposed about the longitudinal axis of the stud member, saidprojections being provided with an overall conical shape,

b. a stud housing having an internally-threaded portion which is adaptedto mate with the projections of the stud member when the projections areforced radially outwardly, the minor diameter of the internally-threadedportion of the stud housing being greater than the major diameter of theexternally-threaded portion of the projections,

c. a piston member adapted to be positioned within the projections ofthe stud member adjacent the end portions of the projections to forcethe projections radially outwardly so that the threaded projections ofthe stud member engage the corresponding intemally-threaded portion ofthe stud housing and e (1. means for displacing the piston member toallow the projections of the stud member to move inwardly and assumetheir original conical shape so that the projections of the stud memberare disengaged from the internally-threaded portion of the stud housing.

11. The system of claim 10 wherein the intemallythreaded portion of thestud housing has an overall cylindrical shape.

12. The system of claim 11 wherein the piston member is displaced withinthe stud member.

13. The system of claim 11 wherein the piston member is displacedoutwardly from the stud member.

Patent No. 3, 696, 488 Dated October 10, 1972 Inventor(s) Michael F.Steele and John S. Yates It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Claim 3, line 1, change claim 3" to -claim 2-.

Signed and sealed this 13th day of February 1973.

(SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM (0459) USCOMM-DC 6O376-P69 US. GOVERNMENT PRINTINGOFFICE I 955 0-356-354.

1. A separation system comprising: a. a stud member having a pluralityof externally threaded projections disposed about the longitudinal axisof the stud member, said projections having end portions which aredisplaceable inwardly relative to said longitudinal axis, b. a pistonmember movably mounted within the stud member and retained by saidprojections at their end portions, said piston member being of such sizeas to maintain said projections in a position parallel to saidlongitudinal axis, c. threaded means for engaging saidexternally-threaded projections, and d. said piston being movable in adirection along the longitudinal axis of the stud member relative tosaid projections to permit said projections to become disengaged fromsaid threaded means, thereby to separate said stud member from saidthreaded means.
 2. The system of claim 1 wherein the projectionsnormally have an overall conical shape.
 3. The system of claim 3 whereinsaid threaded means includes a stud housing having aninternally-threaded portion which is engageable with the threadedprojections of said stud member when the projections are in a positionparallel to said longitudinal axis.
 4. The system of claim 3 wherein themajor diameter of the threaded projections of the stud member isnormally less than the minor diameter of the internally-threaded portionof the stud housing.
 5. The system of claim 4 further including meansassociated with said stud housing for displacing the piston memberwithin the stud member.
 6. The system of claim 4 further including meansassociated with said stud housing for displacing the piston memberoutwardly from the stud member.
 7. The system of claim 1 wherein saidthreaded means includes a stud housing having an internally-threadedportion which is engageable with the threaded projections of said studmember.
 8. The system of claim 7 further including means associated withsaid stud housing for displacing the piston member within the studmember.
 9. The system of claim 7 further including means associated withsaid stud housing for displacing the piston member outwardly from thestud member.
 10. A separation system comprising: a. a stud member havinga plurality of externally-threaded projections disposed about thelongitudinal axis of the stud member, said projections being providedwith an overall conical shape, b. a stud housing having aninternally-threaded portion which is adapted to mate with theprojections of the stud member when the projections are forced radiallyoutwardly, the minor diameter of the internally-threaded portion of thestud housing being greater than the major diameter of theexternally-threaded portion of the projections, c. a piston memberadapted to be positioned within the projections of the stud memberadjacent the end portions of the projections to force the projectionsradially outwardly so that the threaded projections of the stud memberengage the corresponding internally-threaded portion of the stud housingand d. means for displacing the piston member to allow the projectionsof the stud member to move inwardly and assume their original conicalshape so that the projections of the stud member are disengaged from theinternally-threaded portion of the stud housing.
 11. The system of claim10 wherein the internally-threaded portion of the stud housing has anoverall cylindrical shape.
 12. The system of claim 11 wherein the pistonmember is displaced within the stud member.
 13. The system of claim 11wherein the piston member is displaced outwardly from the stud member.